If I recall correctly, we had something of a hacky remoting stopgap that should have worked. If it doesn't, we need to fix it. Will chat with bent/sicking. There were longer-range plans for a better one but scheduling that is harder. In this case, we should enable the tests.
But I don't remember correctly and there wasn't a hacky remoting stopgap, OK, makes sense to have them off.

IDL (allegedly) works in e10s, in a single process (I haven't actually tried it myself, wouldn't be surprised if we broke it). The tests set preferences and permissions though, which is why they don't work.

We have support for cross-process friendly pref-setting now. ISTR we did the same for permissions. We really need to get these tests back on: one product (firefox/mobile/tablet) is currently shipping the code (apparently completely untested) and will continue to do so for the foreseeable future, and another product (b2g) will soon be shipping it.

I have ran these recently without this patch and 3 tests timeout and the rest take a long time, before we turn these on, can we make a pass through to ensure these tests are running without major kinks to slow them down?

There are a few tests which run noticeably slower on android:
test_add_put.html
test_complex_keyPaths.html
test_clear.html
test_index_update_delete.html
And there are a few that timeout:
test_deleteDatabase.html
test_deleteDatabase_interactions.html
test_file_os_delete.html
These are all unrelated to the patch, but related to getting indexedDB tests running on android.

Comment on attachment 632030[details][diff][review]
Fix.
[Approval Request Comment]
Bug caused by (feature/regressing bug #): IndexedDB (been around forever)
User impact if declined: Some databases may persist after pages request their deletion.
Testing completed (on m-c, etc.): Good tests on m-c, even fennec.
Risk to taking this patch (and alternatives if risky): This is a very small and very safe patch. I don't expect any risk, to be honest.
String or UUID changes made by this patch: None.